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Trichomonas Testing

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Also known as: T. vaginalis; Wet Prep
Formal name: Trichomonas vaginalis; Trichomonas vaginalis RNA; Trichomonas vaginalis Culture; Trichomonas vaginalis DNA Probe; Trichomonas vaginalis by Amplified Detection; Trichomonas vaginalis by Direct Fluorescent Antibody (DFA)

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The Test Sample

What is being tested?

Trichomonas vaginalis is a single cell (protozoan) parasite that cannot be seen by the naked eye (microscopic). It causes vaginal infections in women and, in men, infections of the urethra, the tube that carries urine from the bladder to outside the body, and inflammation of the prostate (prostatitis). Trichomonas testing detects the parasite in samples from the vagina or penis to diagnose an infection.

According to the Centers for Disease Control and Prevention (CDC), trichomoniasis, which is caused by the infection, is one of the most common, curable sexually transmitted diseases (STDs). In the U.S., an estimated 3.7 million people have the infection, but only about 30% develop any symptoms. Symptoms are more common in women than in men.

Trichomonas vaginalis is one of the most common causes of vaginitis (inflammation of the vagina) in women. When they occur, symptoms include:

  • Itching, irritation, soreness of the vagina, or a burning sensation
  • Frothy, yellow-green or grey vaginal discharge
  • Foul-smelling vaginal discharge
  • Frequent urge to urinate
  • Possible blood-spotting from the vagina
  • Itching of inner thighs
  • Discomfort during intercourse

In men, symptoms may include:

  • Burning after urinating or ejaculating
  • Itching or irritation of the urethra
  • Discharge from the urethra

These symptoms may take 5 to 28 days after exposure to an infected person or longer to develop; however, once diagnosed, trichomoniasis is easily treated with prescription antibiotics. During treatment, an infected person should cease sexual activity and inform partners so that they can also be treated and prevent re-infection.

How is the sample collected for testing?

For women, a healthcare practitioner may use a swab or small brush to collect a sample of cells or secretion from the vagina during a pelvic examination. Sometimes, the sample may be obtained from the collection vial used for a Pap smear.

Urine is recommended for men, but can also be used for women. As you begin to urinate, collect the initial portion of your urine stream (first-catch) in a container provided by the healthcare practitioner or laboratory.

Sometimes for men, a healthcare practitioner may use a swab or brush to collect a sample of cells or secretion from the urethra.

NOTE: If undergoing medical tests makes you or someone you care for anxious, embarrassed, or even difficult to manage, you might consider reading one or more of the following articles: Coping with Test Pain, Discomfort, and Anxiety, Tips on Blood Testing, Tips to Help Children through Their Medical Tests, and Tips to Help the Elderly through Their Medical Tests.

Another article, Follow That Sample, provides a glimpse at the collection and processing of a blood sample and throat culture.

Is any test preparation needed to ensure the quality of the sample?

No test preparation is needed.